To counter Stephen Elop’s remark that by joining forces, Nokia NOK and Microsoft MSFT were going to make it a “three horse race” — implying that Apple’s AAPL iOS and Google’s GOOG Android were the only other viable mobile ecosystems in the running — Asymco‘s Horace Dediu did some digging and produced the chart at right.

It shows the lifespan of 16 major mobile operating systems, several of which have died and two more — Symbian and MeeGo — that Nokia seems ready to put out to pasture.

“What I find noteworthy,” writes Dediu, “is that there is an implied peculiar fatalism about the market when only two platforms are considered viable, neither of which are more than 3 years old. While visiting the Mobile World Congress, I sensed this jumping to conclusions about platforms was eerily similar to that of a few years ago when new entrants like Apple and Google were declared dead on arrival.”